Degradable polymers are highly desirable due
to the tremendous growth of polymer wastes. Some polymers could be degraded
under strong acidic or basic conditions toward unknown or unvalued products (<i>i.e.</i> downcycling). New methods to
degrade polymers into monomers or high-value-added materials (<i>i.e.</i> upcycling) are more preferred for
sustainable developments. In this work, linear and cross-linked
poly(alkynoate)s were
successfully degraded by benzamidine with 100% conversion into not only diols,
a kind of monomers, but also high-value-added <i>N-</i>heterocyclic compounds of pyrimidone and imidazolone derivatives in
high yields through
controlling the reaction conditions. Notably,
thanks to the AIE feature of the degraded products, the degradation process
could be visualized under UV light via gradually increased luminescent
intensity of the reaction mixtures, which facilitates
the monitoring of the polymer degradation.
Using this highly efficient degradation reaction, fluorescence patterns could
be generated through microcontact printing (μCP) of the stamp on the thin films of poly(alkynoate)s. Moreover,
the pyrimidone derivatives
could be applied in bioimaging
and inhibiting bacteria, and the imidazolone
derivatives could be used for the
detection and recovery of gold (III) ions from electronic waste and serve as
the fluorescent sensor to detect <i>in situ </i>generated
amines from food spoilage. Thus, this work presents a visualized and high value
product-selective degradation to solve the end-of-life issue of polymers.